UNFfine60° flank

#5-44 UNF Thread Dimensions

#5-44 UNF is a fine pitch UNF thread. There are 44 threads per inch, giving a pitch of 0.58 mm. The recommended tap drill leaves roughly 75% thread engagement.

Nominal Ø3.17 mm
Pitch0.58 mm
Threads per inch44
Pitch Ø-6.35 mm
Tap drill-11.49 mm

Thread profile

millimetres unless stated
Thread profile — #5-44 UNFd 3.17d2 -6.35d3 -14.81mm60°P 0.58h3 8.99tap ⌀-11.49
#5-44 UNF — basic profile60° flank angle · Not to scale
Designation
#5-44 UNF
Thread system
UNF
Series
fine
Flank angle
60°
Major diameter
3.17 mm / 0.12"
Pitch
0.58 mm
Threads per inch
44
Pitch diameter
-6.35 mm
Minor diameter (external)
-14.81 mm
Minor diameter (internal)
-12.7 mm
Thread depth
8.99 mm
Recommended tap drill
Ø -11.49 mm / -0.4523"

How these values are derived

Basic ISO thread geometry uses the fundamental triangle height H = 0.866025 × P. External minor diameter d₃ = d − 1.226869 × P, internal minor diameter D₁ = d − 1.082532 × P. Tap drill is given as nominal diameter minus pitch, which approximates a 75% thread engagement — adjust for tough materials or deep holes.